Many types of rotary lawn mowers are known. Such equipment may generally be classified as walk-behind mowers or riding mowers, both of which typically include one or more cutting decks which perform the actual mowing operation. The mower may also include a grass catcher connected to the cutting deck by a conduit for collecting grass clippings generated by the cutting deck. Riding lawn mowers generally have larger grass catchers capable of collecting and carrying more grass clippings. The present invention relates specifically to riding mowers with grass catching systems and the remainder of the discussion will focus accordingly.
Mowing decks are often convertible between: a mulching mode, where clippings are returned directly to the lawn by the cutting deck; a discharge mode, where clippings are discharged outwardly from the cutting deck; and a bagging or catching mode, where clippings are delivered from the cutting deck to the grass catcher. If the grass to be cut is long, it may be difficult to operate the mower in mulching mode without leaving large clumps of grass on the lawn. In such conditions, it is often desirable to collect the clippings in the grass catcher so as to produce a lawn with a more manicured appearance. While the catching mode can provide a more aesthetically pleasing lawn, it has a drawback. Particularly, the collection of clippings necessarily requires that the catcher be periodically emptied as it becomes full. If the catcher is not emptied upon reaching its full condition, the catcher and the conduit extending between the deck and the catcher can become clogged with clippings. Emptying the catcher and clearing the conduit can then become troublesome. Thus, it is desirable for the catcher to have a high clippings capacity and an effective method of dispersing the clippings within the catcher to ensure even, optimal filling. A catcher with these characteristics does not need to be emptied as often as a smaller, less efficient catcher. Ideally, the grass catcher would have a method of alerting the operator to a full catcher condition to prevent catcher/conduit clogging.
Grass catchers generally have a means for admitting air and clippings transported to the catcher from the cutting deck and for exhausting air out of the catcher after the clippings have been deposited therein. Preferably, the air passes through the catcher with relative ease so as not to create substantial back pressure within the catcher and conduit. Accordingly, the catcher should have an effective filtering means that permits continual passage of air while preventing the discharge of entrained clippings. Ideally, the filtering means is removably mounted within the catcher to facilitate cleaning and replacement.
Another preferred feature of a grass catching system is the ability to discharge the air exiting the catcher in a direction away from the operator. Although the discharged air is preferably free from clippings and debris, it is generally perceived that directing this air away from the operator is desirable as it improves operator comfort. Preferably, the air discharge should be directed toward the rear of the mower in a downward direction. This ensures that air or debris that passes through the filtering system is not projected beyond an area immediately surrounding the mower.
Because of the increased size of grass catchers used on riding mowers, it is advantageous to provide a means for assisting the operator in emptying clippings once the catcher becomes full. For example, the catcher may tilt so that the clippings exit the catcher more easily.
Furthermore, the versatility to use the same mower in either the discharge mode or the catching mode is highly desirable. The mower should be able to switch between operating modes with minimal operator intervention. Ideally, physical disconnection or removal of the catcher would not be required. When operating in the discharge mode, the mower should disperse the clippings evenly over the lawn.
Applicants are aware of several grass catchers that have been tried in the past. Although each is commendable for addressing one or more of the particular issues discussed above, shortcomings are evident with each.
U.S. Pat. No. 3,716,977 issued Feb. 20, 1973 to Jackson and assigned to McDonough Power Equipment, discloses a riding mower and a grass catcher. The grass catcher includes a grass collecting bag made of a woven, porous material that permits exhaust air to pass through while it retains clippings and debris.
U.S. Pat. No. 3,722,192 issued on Mar. 27, 1973 to Corbett, discloses a walk-behind lawn mower with a perforate cowl. A hood placed above the cowl acts as an air deflecting shield for exhaust air.
U.S. Pat. No. 4,819,417 issued on Apr. 11, 1989 to Bryant et al. and assigned to F. H. and H. Limited, discloses a large, barrel shaped grass catcher for use with a riding lawn mower. The grass catcher includes an exhaust port and a cylindrical screen positioned below the port. The screen acts as a filter to reduce the escape of grass clippings through the port.
U.S. Pat. No. 4,310,998 issued to Cuba on Jan. 19, 1982 and assigned to Gilson Brothers Company, discloses a grass catcher for a riding lawn mower. The grass catcher includes a filter assembly which uses wire mesh or other suitable material as a filter media. The filter stops grass clippings from passing through the discharge passage. A deflector hood deflects clippings and air entering the catcher. Air is exhausted through a downwardly facing port at the rear of the grass catcher.
U.S. Pat. No. 5,195,310 issued to Kettler et al. on Mar. 23, 1993 and assigned to Deere and Co., discloses a grass catcher for use with a lawn tractor. The grass catcher includes discharge ports and a screen for filtering clippings from the exhaust air before it is discharged through the ports. The discharge ports exhaust air in a downward direction relative to the catcher.
U.S. Pat. No. 4,969,320 issued Nov. 13, 1990 to Langford and assigned to The Toro Company, discloses a grass level checker for a grass catcher. The Langford grass catcher requires the operator to manually manipulate the level checker. As the grass catcher fills, the grass level checker is subject to increased resistance to operator manipulation. Accordingly, the operator can determine, based on the resistance of the level checker, the amount of accumulated grass within the catcher. The Langford grass catcher includes grass bags made of a loosely woven polyester. The bags are configured to accept plastic lawn debris bags for accepting clippings and debris from the cutting deck. An exhaust port permits passage of exhaust air that has passed through the filtering screen.
U.S. Pat. No. 4,964,266 issued to Kolb on Oct. 23, 1990 and assigned to Wolf-Gerate GmbH, discloses a grass catcher attached to the frame of a walk-behind lawn mower. The grass catcher includes a sensor for sensing a full condition within the catcher. The sensor may be a capacitive, inductive or resistance sensor which measures the grass collected in the mouthpiece. The sensor could also be an infrared sensor which senses infrared radiation, or it could be a pressure sensor. The sensor is connected to an electronic evaluation circuit that produces an optical or acoustic warning signal to the operator. The sensor is positioned near the inlet of the grass catcher.
U.S. Pat. No. 5,321,939 issued to Fuse et al. on Jun. 21, 1994 and assigned to Honda discloses a riding lawn mower with a grass catcher. The grass catcher receives grass clippings from the cutting deck. The grass catcher includes a light sensor mounted in the upper cylindrical body of a "shooter" (the conduit which delivers air and clippings into the catcher). The sensor includes a light emitting portion and a light receiving portion. If the receiver and the accompanying controller sense a light blocking condition for a period of time exceeding a predetermined value, then a full condition warning lamp and buzzer are activated to alert the operator of a full catcher condition. The full condition sensed would, of course, be at the location of the sensor which is at the end of the shooter. A slightly different embodiment is shown in FIG. 7 where the sensor is mounted on tabs located just outside of shooter.
U.S. Pat. No. 4,922,696 issued to Burns et al. on May 8, 1990 and assigned to The Murray Ohio Manufacturing Company discloses a riding lawn mower with a grass catcher attached. The grass catcher includes a vertically elongated transparent window for the operator to view the clipping level within the catcher
U.S. Pat. No. 5,425,223 issued to DeLaRonde on Jun. 20, 1995 discloses an indicator means to detect blockage of a duct used to transport clippings from a cutting blade to a grass catcher. A flag member is raised to a generally perpendicular position relative to the duct when air is flowing freely through the duct. When the flow of air through the duct is reduced or stopped due to a blockage in the duct, the flag falls from its generally perpendicular position, thus visually alerting the operator of an unsatisfactory air flow condition.
U.S. Pat. No. 5,605,033 issued to Olmr on Feb. 25, 1997 discloses a riding lawn mower with a grass catcher. The grass catcher includes a detector with a pressure activated switch which is responsive to a pressure condition in a conduit for conveying clippings and air to the catcher. When the static pressure in the conduit increases due to a full catcher condition, the switch closes. This activates a circuit which disables the rotation of the cutting blade.
U.S. Pat. No. 4,589,249 issued to Walker et al. on May 20, 1986 and assigned to Walker Manufacturing Co. discloses a riding lawn mower with a catcher for catching grass clippings. The catcher can be raised and tipped as shown in FIG. 5. When raised and tipped, the catcher door opens allowing the accumulated clippings to fall from the catcher. The catcher also includes a detector. The detector is mounted on the catcher and is described as a horn or beeper that is actuated by a pressure responsive switch. The switch is apparently coupled into the interior portion of the conduit. The horn or beeper is probably activated when back pressure in the conduit rises as a result of a full catcher condition.
U.S. Pat. No. 3,974,631 issued to Rhodes et al. on Aug. 17, 1976, and assigned to J. I. Case Company, discloses a grass catcher mounted on a riding mower. The grass catcher includes a deflector for promoting substantially equal distribution of grass clippings to the grass collection containers. Air exhaust plates have suitable openings for allowing passage of exhaust air while retaining clippings and other debris in the catcher. The '631 patent also discloses a catcher emptying system that permits the clipping carrying portion of the catcher to pivot away from the mower.
The present invention provides a novel lawn mower grass catcher that is summarized below.